My son and I went to range today to shoot and here is the report. I was shooting my Ruger GP100, 6" barrel. I used 38 special FMJ 158 grain rounds from bulkammo.com. This is remanufactured by MBI and I paid $22.50/100 rounds.
This target is 12 rounds from a bench at 10 yards.
This target is 6 rounds (same stuff) shot off-hand, same distance, standing.
I have noticed all the shots are a bit low and I need to adjust rear site. The center red bull is 1.65"/4.2 cm. The one high round in the off-hand target was a "pulled" shot - the first one before I settled down. There are 5 rounds in the lower group - 2 went through the 8 ring lower group.